Hi i Have a boiler mate II it was fitted about 10-12 years ago . about a year ago we noticed a slight tinge of yellow in our hot water and ocasional bits in the water. This has steadily got worse. I had a look on several web sites which suggested limescale build up was a cause for this in standard systems or sludge in the bottom of the imersion tanks (these were american sites). I remembered the plumber recomending a salt based water softner which he placed under the floor boards when the system was installed. I found this and also read it should have been changed after 2 years. I also noted that if you ran the water the water started clear then went yellow then went clear again and was fine until you leave it for a few hours then the yellow returned. I removed the water softner and found that it was full of yellow sludge. I have replaced this with magnetic watersoftner now. But we are still getting a period of yellow water with little metalic looking flecks (i thing these maybe lime scale but not sure) a few seconds after the hot tap starts running. This lasts a couple of minutes and the water clears. We have plenty of hot water i would say the pressure is not what it was when we first got the system, buts its still leaps and bounds better than a comby pressure. Can any one confirm that this is lime scale and not a bleed through from the central; heating water and can anyone suggest how to get rid of it? Thanks Mike